• International Journal of Aeronautical and Space Sciences
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• v.17 no.2
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• pp.260-267
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• 2016

The design process of blended inlet body (BIB) for the preliminary design of a near-space high supersonic unmanned aerial vehicle (HSUAV) is presented. The mass flow rate and cowl area of inlet at a design point are obtained according to the cruise condition of the HSUAV. A mixed-compression axisymmetric supersonic inlet section with a fixed geometry reasonably matching the high supersonic cruise state is created by using the inviscid theory of aerodynamics. The inlet section is optimized and used as a baseline section for the BIB design. Three BIB concepts for the HSUAV are proposed, and their internal aerodynamic characteristics of inlet are evaluated using Euler computational fluid dynamics (Euler CFD) solver. The preferred concept is identified, in which the straight leading edge of the baseline HSUAV configuration is modified into the convex leading edge to accommodate the inlet and meet the requirements of the cowl area to capture the sufficient air flow. The total recovery of inlet for the preferred BIB concept and the aerodynamic characteristics of the modified HSUAV configuration are verified using Navier-Stokes computational fluid dynamics (NS CFD) solver. The validation indicates that the preferred BIB concept can meet both the requirements of the inlet and aerodynamic performance of the HSUAV.

• International Journal of Precision Engineering and Manufacturing
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• v.2 no.2
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• pp.57-64
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• 2001

In recent years, the concern of designing multi-stage gear drives ha increased with more application of them in high-speed and high-load. Until now, however, the researches on the design of gear drives have been focused on single gear pairs. Thus the design practice for multi-stage gear drives has been depended on experiences and expertise of designers and carried out commonly by trial and error. We propose an automation algorithm for the design of two-and three-strage cylindrical gear drives. The two types of dimensional design processes have been proposed to determine gear dimensions in a formal way. The first design process(Process I) uses to total volume of gears to determine gear ration , and uses K factor , unit load and aspect ration to determine gear dimensions, The second one(Process II) makes use of Niemann's formula and center distance to calculate gear ratio and gear dimensions. Process I and Process II employ material date from AGMA and ISO standards, respectively. The configuration design determines the positions of gears with minimizing the volume of gearbox by using a simulated annealing algorithm. The availability of the design algorithm is validated by the design examples to two-and three=stage gear drives.

• Journal of the Korean Society of Systems Engineering
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• v.9 no.2
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• pp.83-90
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• 2013

Integrated aircraft synthesis process for rapid analysis and design is described in this paper. Data flow between different analysis fields is described in details. All the data are divided into several groups according to importance and source of the data. Analysis of design requirements and certification regulations is carried out to determine baseline configuration of an aircraft. Overall design process can be divided into initial sizing, conceptual and preliminary design phases. Basic data for conceptual design are obtained from initial sizing, CAD and geometry analysis. Basic data are required input for weight, aerodynamics and propulsion analyses. Results of this analysis are used for stability and control, performance, mission, and load analysis. Feasibility of design is verified based on analysis results of each discipline. Design optimization that involves integrated process for aircraft analysis is performed to determine optimum configuration of an aircraft on a conceptual design stage. The process presented in this paper was verified to be used for light aircraft design.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.19 no.3
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• pp.1-9
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• 2011

In this paper, a conceptual design process for Very Light Jet aircraft has been proposed incorporating aircraft safety certification. During the proposed design process, satisfaction of the airworthiness certification for an intermediate resulting aircraft configuration is evaluated and then redesigns are carried out if necessary and until the designed aircraft configuration satisfies the airworthiness requirements. Certification database has been developed using FAR 23, AC 23, KAS 23, and CS 23 as the airworthiness certification. Based on the developed certification database Design Certifcation Related Table has been produced to use the airworthiness requirements as design constraints in the propsed design process. Using Quality Function Deployment the design variables for a redesign are carefully selected and a design optimization is performed. To demonstrate the feasibility and effectiveness of rapid aircraft conceptual design using the proposed approach, a Very Light Jet design optimization including a redesign of wing flap has been performed and the design results have been presented.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.10
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• pp.4733-4738
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• 2013

This paper proposes a method to obtain the dynamic equilibrium configuration of a constrained mechanical system by using multibody dynamic analysis. Dynamic equilibrium equations with independent coordinates are derived from the time-dependent constraint equations and dynamic equations of a multibody system. The Newton-Raphson method is used to find numerical solutions for nonlinear algebraic equations that are composed of the dynamic equilibrium and constraint equations. The proposed method is applied to obtain the dynamic equilibrium configuration of a speed governor, and the results are verified on the basis of the results from conventional dynamic analysis. Furthermore, vertical displacements at equilibrium configuration, which varied with the rotational velocity of the speed governor, are calculated, and design parameter analysis of the equilibrium configuration is presented.

• Korean Institute of Interior Design Journal
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• v.22 no.4
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• pp.149-157
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• 2013

As a period of pluralism, today's museum architecture has been expanding social and cultural meaning. So, Various expressions are appearing in museum architecture. Accordingly, the museum must be very reproducible and comply with aesthetic requirements. At the same time, museum construction in urban design and features must satisfy professional requirements. SANAA is one of contemporary architects has been decisively deleted existing fixed and functional layout type of program through 'The new hierarchy'. Thus, the experience of the space will vary. Now, museum space is urgently needed than ever before crustal movements. Thus, this study aims to contribute an alternative to the museum space configuration according to the trend of the times through 'The new hierarchy' of SANAA. This paper is limited to the cases of the SANAA's museum architecture. We analyze the characteristics of representation on 'The new hierarchy' appear in the museum space configuration and then, examine the value of the spatial. SANAA's 'New Hierarchy' is going to set the cognitive boundary by expression targeting plane and the surface. It is completely different than the previous boundaries. Characteristics of the expression represents non-centrality, decentrally, non-oriented, uncertainty, non-territorialization, uniformity. It is steady that identity of Space, Human, Environment in Museum. They have a relationship each concept of Independence, autonomy, equality.

• IE interfaces
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• v.11 no.3
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• pp.23-40
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• 1998

In this paper, a method to determine the optimal configuration of operating policies in an integrated-automated manufacturing system using the Taguchi method and computer simulation experiments is presented. An integrated-automated manufacturing system called direct-input-output manufacturing system(DIOMS) is described. We only consider the operational aspect of the DIOMS. Four operating policies including input sequencing control, dispatching rule for the storage/retrieval(S/R) machine, machine center-based part type selection rule, and storage assignment policy are treated as design factors. The number of machine centers, the number of part types, demand rate, processing time and the rate of each part type, vertical and horizontal speed of the S/R machine, and the size of a local buffer in the machine centers are considered as noise factors in generating various manufacturing system environment. For the performance characteristics, mean flow time and throughput are adopted. A robust design experiment with inner and outer orthogonal arrays are conducted by computer simulation, and an optimal configuration of operating policies is presented which consists of a combination of the level of each design factor. The validity of the optimal configurations is investigated by comparing their signal-to-noise ratios with those obtained with full factorial designs.

• Korean Journal of Optics and Photonics
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• v.28 no.6
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• pp.263-272
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• 2017

To design a wide-field optical system, the inverted telephoto configuration, which has a negative front group and a positive rear group, is popular. For a two-mirror system, the inverse Cassegrain system has the inverted telephoto configuration, but the inverse Cassegrain system with the conventional, axially symmetric configuration shows severe field screening and ray obstruction. To avoid these problems, we put the aperture stop on the secondary mirror of an inverse Cassegrain system to increase field of view, and designed a wide-field off-axis two-mirror system which only uses the off-axis field, without ray obstruction.

• Aerospace Engineering and Technology
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• v.12 no.1
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• pp.73-80
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• 2013

In this study, a numerical analysis based on CFD methods has been conducted to predict the aerodynamic coefficients and aerodynamic loads of KSLV-II configuration designed at the system design phase. By the effects of exclusion of engine cowls of prior configuration, axial force and normal force decreased and center of pressure was much moved to the nose direction. Also, aerodynamic loads at flight and on the launch pad were predicted for structural load analysis. The computed results will be used for mission analysis and structural analysis at the next design phase.

• Journal of the Korean Society for Railway
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• v.14 no.2
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• pp.116-120
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• 2011

For the train positioning system currently applied in high-speed MAGLEV train systems, it is classified into absolute positioning systems which discontinuously detect train positions, and relative positioning systems which continuously detect train positions. In this paper we analyze the configuration model and the numerical model of the absolute positioning system applied in TRANSRAPID which is a representative high-speed MAGLEV train, and design the two configuration models specific to the recognition structures of absolute positioning systems. We also verify the compatibility of the design models of absolute positioning system through simulation using MATLAB and propose the optimal configuration model of absolute positioning systems for high-speed MAGLEV train system.